System and method for high power diode based additive manufacturing

• US 9,855,625 B2
• Filed: 01/05/2016
• Issued: 01/02/2018
• Est. Priority Date: 03/05/2013
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Inventors: El-Dasher, Bassem S., Bayramian, Andrew, Demuth, James A., Farmer, Joseph C., Torres, Sharon G.
• Primary Examiner(s): SANDERS, JAMES M
• Application Number:
  US14/988,190
• Publication Number:
  US 20160129503A1
• Time in Patent Office: 728 Days
• CPC Class Codes: B22F 10/20 Direct sintering or melting
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/30 Process control
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 12/43 pulsed; frequency modulated
• CPC Class Codes: B22F 12/44 characterised by the configuration of the radiation means
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B23K 26/042 Automatically aligning the laser beam
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/0643 comprising mirrors
• CPC Class Codes: B23K 26/066 by using masks
• CPC Class Codes: B23K 26/144 the fluid stream containing particles, e.g. powder
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C22C 32/0026 Matrix based on Ni, Co, Cr or alloys thereof
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.

Claims

1. A method for performing Additive Manufacturing (AM) comprising:

irradiating a first powdered material layer of a substrate using an electromagnetic signal sufficient to induce a material phase change of at least a substantial portion of an entire two dimensional area within which the substrate is positioned;

using a dynamically controllable, two dimensional digitally electronically addressable mask for receiving the electromagnetic signal and controllably selecting portions of the electromagnetic signal passing therethrough such that first portions of the electromagnetic signal pass through the mask without selection, and thus reach the powdered material layer without being altered, and second portions of the electromagnetic signal pass through the mask but are selected for rejection, and thus do not reach the powdered material layer;

placing a second powdered material layer over the first powdered material layer;

irradiating the second powdered material layer using the electromagnetic signal while using the mask to selectively block additional portions of the electromagnetic signal from reaching the second powdered material layer of the substrate;

wherein the using a mask to selectively block portions of the electromagnetic signal comprises using a digitally electronically addressable mask;

wherein the using a digitally electronically addressable mask comprises;

using a liquid crystal module to rotate the first portions of the electromagnetic signal while allowing the second portions of the electromagnetic signal to pass therethrough in an unrotated condition; and

using a polarizing element downstream of the liquid crystal module to reject a selected one of the first portions or the second portions, and thus impede the selected one of the first or second portions from reaching the substrate;

further including using an electronically addressable spray source to deposit at least two different material types to form at least one of the first and second powdered material layers; and

further controlling the mask in accordance with the at least two different material types being irradiated.

2. The method of claim 1, wherein the irradiating a powdered layer of a substrate using an electromagnetic signal comprises using a diode array to generate the electromagnetic signal.

3. The method of claim 2, wherein the using the diode array comprises using a diode array configured to generate a power density of at least about 10 kW/cm².

4. The method of claim 1, further comprising using a computer to control the digitally electronically addressable mask.

5. The method of claim 2, further comprising using a computer to control the diode array.

6. A method for performing Additive Manufacturing (AM) comprising:

generating an electromagnetic signal toward a powdered material forming a substrate, wherein the electromagnetic signal is sufficient to induce a material phase change of an entire two dimensional area of the substrate;

using a liquid crystal polarization rotator to receive the electromagnetic signal before the electromagnetic signal reaches the substrate;

controlling the liquid crystal polarization rotator to act as a mask by;

controlling a first component of the liquid crystal polarization rotator to receive and rotate a first portion of the electromagnetic signal passing therethrough while allowing a second portion of the electromagnetic signal to pass therethrough without being rotated;

controlling a second component of the liquid crystal polarization rotator to reject one of the first or second portions of the electromagnetic signal received from the first component, and thus to prevent the one of the first or second portions of the electromagnetic signal from reaching the powdered material, while the second component allows the other one of the first or second portions of the electromagnetic signal to reach the powdered material;

wherein the controlling a first component of the liquid crystal polarization rotator to receive and to rotate a first portion of the electromagnetic signal comprises using a liquid crystal module; and

wherein the controlling a second component of the liquid crystal polarization rotator to reject one of the first or second portions of the electromagnetic signal comprises using a polarizer;

further including providing the powdered material as a first material type;

providing an additional powdered material as a second material type different from the first material type;

using an electronically addressable spray source to sequentially deposit the first and second material types to form first and second layers; and

further controlling operation of the mask depending on the first and second material types to melt each of the first and second material types.

7. The method of claim 6, wherein the operation of generating an electromagnetic signal comprises using a diode array.

8. The method of claim 6, wherein the operation of using a liquid crystal module comprises using a computer controllable liquid crystal module.

9. The method of claim 6, wherein the operation of using a polarizer comprises using a polarization mirror.

10. The method of claim 6, wherein the operation of generating an electromagnetic signal comprises using a diode array to generate a pulsed electromagnetic signal.

11. A method for performing Additive Manufacturing (AM) comprising:

using a laser diode to generate an electromagnetic signal toward a first layer of powdered material forming a substrate, wherein the electromagnetic signal is sufficient to irradiate an entire two dimensional area of the powdered material;

using a liquid crystal polarization rotator having a liquid crystal module and a polarizer to receive the electromagnetic signal before the electromagnetic signal reaches the first layer of powdered material;

controlling the liquid crystal polarization rotator to act as a mask by;

controlling the liquid crystal module to rotate a first portion of the electromagnetic signal passing therethrough while allowing a second portion of the electromagnetic signal to pass therethrough without being rotated;

controlling the polarizer to reject one of the first or second portions of the electromagnetic signal received from the liquid crystal module, and thus to prevent the one of the first or second portions of the electromagnetic signal from reaching the first layer of powdered material, while the polarizer allows the other one of the first or second portions of the electromagnetic signal to reach the first layer of powdered material and to melt the first layer of powdered material;

subsequent to melting of the first layer of powdered material, applying a second layer of powdered material on at least a portion of the first layer of powdered material; and

using the laser diode and the liquid crystal polarization rotator to melt at least a portion of the second layer of powdered material;

further including using an electronically addressable spray source to deposit at least two different material types to form at least one of the first and second powdered material layers; and

further controlling the mask in accordance with the at least two different material types being irradiated.

12. The method of claim 11, further comprising using a computer to control the liquid crystal polarization rotator.